Pneumatic hammer



April 27 1926.

$- KUSUNOKI ET AL PNEUMATIC HAMMER Filed Dec. 6, 1920 s Sheets-Sheet 2 f/BE 75 1e IO 28 l\l lllll ll "5 Kusunolzi. f S,yamqmo1;0

lvwantozs 5%. 664% PNEUMATIC HAMMER Filed Dec. 6., 1920 3 Sheets-Sheet 5 amamtots f/fii/w/a Patented Apr. 27, 1%.26.

UNITE.

SHUSAKU KUSUNOKI, or rnnrnorunn or nrnosnnvm, AND snrar YAMAMOTO, or

KUBE,

JAPAN;

v rainwat-Arro HAMMER.

Application filed December Hammers, of which the following is a speci fication. p i

This invention relates to improvements'in pneumatic hammers.

One object ot'the invention'is to furnish a pneumatic hammer having a longer stroke 'fOI its length than pneumatic hammers of known constructions.

A further object isto provide a pneumatic hammer in which the compressed air is directly admitted. to the hammer cylinder, that is, the air is admitted to the hammer chamber without passing through any tortuous passageways, the friction of which would decrease the air pressure.

' A still further object is to providea pneumatic hammer having improved means for lubricating the working parts.

With 'the foregoing objects outlined and with other objects in view which will appear asthe description proceeds. the invention oonsistsin the novel features hereinafter described in detail, illustrated in the accompanying drawings and more particularly pointed out in the appended claim.

Figure I is alongitudinal sectional view of a hammer constructed in accordance with the invention, 7

Fig. 2 is a cross section along the line 2-42 of Fig. 1. 1

Fig. 3 is a detail longitudinal sectional view showing the air supply and exhaust valve situated in its lower position in the valve chest. v

Fig. 4 is a cross section along the line 4-4 of Fig. 3. I i

Fig; 5 is a detail longitudinal sectional view showing the air supply and exhaust valve situated in its upper position in the valve chest. I

Fig. 6 is a cross section taken along the line 6-6 of Figure 5.

Fig. 7 is a detail longitudinal sectional view of the handle showing the improved oiling device.

Fig. 8 is a view similar to Fig. 1 showing V the hammer at the end of the forward stroke.

a, ieec. Serial No. 422,75

Fig. 9 is a similar viewbut showing the ammer at the end of the rearward stroke. in the drawing 1 designates the handle of the improved apparatus adapted to be grasped by the operator and provided with a chamber *2 to contain lubricant and closed 'bya plug 3. -This chamber communicates with an oil feeding passageway 4: through which extends a valve stem 11 having a head 5 adapted to close the lower end of said passageway. This valve head is held on its seat by a spring 7 secured in position by a plug 8.; The chambercontaining the spring 7 communicates with a passageway 9.. which extends to an air supply chamber 10. As best shown in Figure 7. the upper end of the valve stem 11 is provided with a push pin 6 and is slidably mounted in a passageway that communicates with a port 12. which admits air to the chamber 2 when the stem 11 is depressed. From the foregoing it will be understood that'thc stem 11 may be de pressed by the operator, and this will. admit air through passageway 12 to the chamber 2 andwill also cause the valve head 5 to leave its seat and permit oil from the" chamher 2 to flow through the passageways-4 and 9 into the air supply chamber 10 from which it may flow to the working parts, when the control valve 13 is closed.

The supply o1 air to the apparatus is com handle 1 by means of cross pin 15. The

valve 13 is moved in one direction by a handlever 16 pivot-ally mounted at 17, and the valve is moved in the opposite direction by a spring 18 held in the handle by a plug 19. The handle is also provided with a fitting 20 adapted to be connected to the air supply hose not shown).

The lower portion of the handle 1 forms a cylindrical extension in which is mounted the automatically operating control valve 21, the valve chest 22 and the valve seat member 23. The valve chest 22 and seatmemher 23 are held in alignment by pins 24 arranged on opposite sides of the hammer cylinder 25 as best shown in Figure 4.

As shown in Figures 3, 4, 5 and 6', the

valve chest 22 is of hollow cylindrical form throttle valve 13 mounted in a t arranged ports 27 which extend from the lower end of the chest to the bore of the latter. Slidably mounted in the chest 22 is the valve 21 which is of larger diameter at its lower end than at its upper end. This valve has it upper end closed and its wall is provided near the closed end with air inlet ports 28. The enlarged lower portion of the valve has an annular groove 29 in its periphcry, and when the valve is in its lower po sition as shown in Figure 3, the compressed air from the supply passageway 10 can flow downwardly through the ports 26. around the groove 29. and into the ports 27, which deliver into the lower portion of the hammer chamber in a manner hereinafter described.

hen the valve 21 is in its upper position as shown in Figures 5 and 9, the air from the hammer chamber may be exhausted through the ports 27 through the groove 29 and into a port 30 provided in the chest 22. From the port 30, the exhaust air may flow into a chamber 31, which surrounds the valve chest 22. and this chamber is in communication with the atmosphere.

The hammer cylinder 25 is provided with longitudinally extending conduits 32 having their upper ends registering with ports in the valve seat 23, which ports are in align ment with the ports 27 in the valve chest 22. This hammer cylinder has its upper end threaded into the cylinder extension of the handle l and is locked in position by means of a bolt' 33.

The hammer cylinder is also provided with conduits 38 opening into the bore of the cylinder as shown at 35 and opening into the chamber 31 as shown at 34;. Arranged in the bore of the hammer cylinder 25 is a hammer proper 36.

lVhen the parts are in the position shown in Figure 1, the raising of the handle 16 will cause the valve 13 to open and admit air from the supply fitting 20 into the supply chamber 10. From this chamber, the air flows by way of the ports 26 into the annular groove 29, thence into the ports 27, and then through the conduits 32 and passageway 37 into the bore 01 the cylinder 25 below the hammer 36. As the air is admitted through the ports 37 into the bore of the cylinder 25, the hammer 36 rises and until it closes the ports 35, it causes the air above the same to pass out of the bore of the cylinder through the passageways 38. hen however, the hammer has been elevated sutficiently to close the ports 35, it will function to compress air in the upper end of said bore, and just before the hammer reaches the upper portion of the valve 21, this air will be compressed sufficiently to raise the valve 21. This is permitted on account of the lower portion of the valve 21 being of greater diameter than the upper portion or" the same.

It will be noted that the hammer 36 in rising will uncover the port 35 so that the air beneath the hammer may then escape by way of the passageways 38.

As soon as the valve 21 is raised. air from the ports 26 will be cut oil? and then the air from chamber 10 will flow directly through the ports 23 into the bore of the valve where it may act directly on the upper end of the hammer 36. As the hammer descends. the air beneath the same will he forced out through the conduits 38 unti the hammer again covers the ports and then the air remaining in the bore of the cylinder 25 below the hammer 36. will be forced upwardly through the conduits 32. ports 27, groove 29, port 30 and chamber 31 to the atmosphere. When the hammer 36 has descended far enough to uncover ports the air in the cvlinder above the hammer will discharge through ports 35 and as a result the pressure above the valve 21 will be greater than the pressure below the valve, and consequently the valve 21 will again descend. It will be noted that the hammer 36 may rise into the bore of the valve 21. so that the stroke of said hammer will be longer than is the case with the hammers of the same length as heretofore constructed. Further, the air compressed between the upper end of the hammer 36 and the valve 21 will provide a cushion to absorb the impact ordinarily present in the upward strolre of the hammer proper. Moreover. the direct admission of the compressed air from the chamber 10 through the ports 28. enables the full force of the air to be realized. If on the other hand it was necessary to lead the air through tortuous passageways the friction set up would decrease the air force.

From the foregoing it is believed that the construction. operation and advantages of the invention may be readily understood by those skilled in the art and it is apparent that various changes may be made in the construction illustrated without departing from the spirit of the invention as expressed in the claim.

hat is claimed and desired to be secured bv Letters-Patent is:

In a pneumatic hammer, a handle member provided with an air chamber and a bore communicating with said chamber, an annular valve chest fitted in the bore and having an internal shoulder near its upper end. upper ports leading from the upper end of the chest to the bore of the latter and placing the chamber in communication with the bore of the chest. lower ports leading from the lower end of the chest to the bore of the latter, an inverted cup-shaped valve slidable in the chest and having an external shoulder to engage the shoulder of the chest and limit the upward movement of the valve, said valve having an annular external groove adapted to place said ports in communication when the valve is lowered, an exhaust port in the chest for discharging air from the groove when the valve is raised, said valve when raised, projecting into said chamber, ports in the wall of the valve to admit air from the chamber directly into the valve when the latter is raised, a cylinder having its upper end fitted into the bore of the handle, a slidable hammer in the cylinder, the bore of the cylinder being of the same diameter as the lower port-ion of the inner surface of the valve to permit the upper end of the hammer to enter the valve, an exhaust conduit placing the intermediate portion of the bore of the cylinder in communication with the atmosphere, and a passageway placing the lower portion of the cylinder bore in communication with the lower ports of the valve chest. I

In testimony whereof they affix their signatures.

SHUSAKU KUSUNOKI. [11. s.] SEIJ I YAMAMOTO. [1 s.] 

